qwt_color_map.h

/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
 * Qwt Widget Library
 * Copyright (C) 1997   Josef Wilgen
 * Copyright (C) 2002   Uwe Rathmann
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the Qwt License, Version 1.0
 *****************************************************************************/

#ifndef QWT_COLOR_MAP_H
#define QWT_COLOR_MAP_H

#include "qwt_global.h"
#include "qwt_interval.h"
#include <qcolor.h>
#include <qvector.h>

class QWT_EXPORT QwtColorMap
{
public:
    enum Format
    {
        RGB,

        Indexed
    };

    QwtColorMap( Format = QwtColorMap::RGB );
    virtual ~QwtColorMap();

    Format format() const;

    virtual QRgb rgb( const QwtInterval &interval,
        double value ) const = 0;

    virtual unsigned char colorIndex(
        const QwtInterval &interval, double value ) const = 0;

    QColor color( const QwtInterval &, double value ) const;
    virtual QVector<QRgb> colorTable( const QwtInterval & ) const;

private:
    Format d_format;
};

class QWT_EXPORT QwtLinearColorMap: public QwtColorMap
{
public:
    enum Mode
    {
        FixedColors,

        ScaledColors
    };

    QwtLinearColorMap( QwtColorMap::Format = QwtColorMap::RGB );
    QwtLinearColorMap( const QColor &from, const QColor &to,
        QwtColorMap::Format = QwtColorMap::RGB );

    virtual ~QwtLinearColorMap();

    void setMode( Mode );
    Mode mode() const;

    void setColorInterval( const QColor &color1, const QColor &color2 );
    void addColorStop( double value, const QColor& );
    QVector<double> colorStops() const;

    QColor color1() const;
    QColor color2() const;

    virtual QRgb rgb( const QwtInterval &, double value ) const;
    virtual unsigned char colorIndex(
        const QwtInterval &, double value ) const;

    class ColorStops;

private:
    // Disabled copy constructor and operator=
    QwtLinearColorMap( const QwtLinearColorMap & );
    QwtLinearColorMap &operator=( const QwtLinearColorMap & );

    class PrivateData;
    PrivateData *d_data;
};

class QWT_EXPORT QwtAlphaColorMap: public QwtColorMap
{
public:
    QwtAlphaColorMap( const QColor & = QColor( Qt::gray ) );
    virtual ~QwtAlphaColorMap();

    void setColor( const QColor & );
    QColor color() const;

    virtual QRgb rgb( const QwtInterval &, double value ) const;

private:
    QwtAlphaColorMap( const QwtAlphaColorMap & );
    QwtAlphaColorMap &operator=( const QwtAlphaColorMap & );

    virtual unsigned char colorIndex(
        const QwtInterval &, double value ) const;

    class PrivateData;
    PrivateData *d_data;
};


inline QColor QwtColorMap::color(
    const QwtInterval &interval, double value ) const
{
    if ( d_format == RGB )
    {
        return QColor( rgb( interval, value ) );
    }
    else
    {
        const unsigned int index = colorIndex( interval, value );
        return colorTable( interval )[index]; // slow
    }
}

inline QwtColorMap::Format QwtColorMap::format() const
{
    return d_format;
}

#endif